(25) Correlation of serum inhibin B and radiographic hemorrhagic cyst: A case for conservative management

Background: Ovarian neoplasms occur 2.6 per 100,000 in the child and adolescent population and are usually benign in nature. The incidence of pediatric ovarian malignancy is poorly understood, as it is exceedingly rare, though when present, adnexal masses are diagnosed as gynecologic malignancy 3-8% of the time. Tumors markers like inhibins can be used to differentiate between benign and malignant lesions. Inhibin B is generally thought to be elevated in granulosa cell malignancies and can be a cause of primary or secondary amenorrhea. No literature, however, has demonstrated an association with an elevation of inhibin B with benign pathologies as discussed in this case.

Case: A 12-year-old female presented to pediatric gynecology with a left adnexal mass incidentally noted on renal ultrasound while undergoing evaluation for pediatric hypertension. Menarche occurred at age 11 with regular monthly cycles. An abdominal ultrasound and CTAP were notable for a 5.3x4.9x4.2cm thin walled cyst in left ovary concerning for hemorrhagic cyst. Labs demonstrated normal estradiol, testosterone, aldosterone, bHCG, inhibin A, and AFP. Inhibin B was elevated to 464. Given patient age and reassuring findings on ultrasound, it was ultimately decided to trend serum inhibins, mass size with ultrasound, and consult pediatric surgery given possible gynecologic malignancy. Repeat imaging 4 weeks later showed a stable hemorrhagic cyst and down trending inhibin B at 180. At 8 weeks from onset, imaging demonstrated interval resolution hemorrhagic cyst and inhibin B at 118. Given the improvements, repeat imaging and inhibin was obtained five months later with no evidence of recurrence of hemorrhagic cyst and normalized inhibin B at 35.

Comments: Limited data exists regarding conservative treatment of adnexal masses that are benign in nature in the setting of elevated tumor markers in pediatric and adolescent patients. In this case, a benign appearing lesion was associated with elevations of inhibin B, which raised concern for gynecologic malignancy. In absence of high-risk ultrasonographic features or symptoms of hyperestrogenism that one would expect in juvenile granulosa cell tumor, the clinical picture was consistent with benign pathology. Thus, inhibin was trended to normal range and correlated with simultaneous resolution of the cyst. An unnecessary surgical procedure was avoided in this asymptomatic patient. Further studies need to be collected to validate the use of trending inhibin B in the setting of benign adnexal pathologies like hemorrhagic cysts.